Infections shrink weapon growth because immunity consumes the same resource pool

Evidence

Weapon growth is extrasensitive to illness, too, for exactly the same reason. Infections drain resources from the surplus pool. Males fighting infections as they develop cannot afford to pour as much into weapon growth. Parasites gnaw away at tissues, pathogens battle the immune system, and all of this gobbles up stored reserves. Weapons and other discretionary structures absorb the brunt of these losses. Antlers grow much smaller in sick males than they do in healthy ones, for example, as do Cape buffalo horns10 and fiddler crab claws. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 343

Categorization

• XREF: connects to: Arms-race weapon growth makes resource trade-offs drastically impair body functions — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 296; Weapon growth is far more resource-sensitive than other body parts — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 340; Growing large weapons diverts resources and stunts other body parts — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295 (+1 more)

Related

• Weapon growth is far more resource-sensitive than other body parts (similarity 0.91)
• Arms-race weapon growth makes resource trade-offs drastically impair body functions (similarity 0.90)
• Growing large weapons diverts resources and stunts other body parts (similarity 0.89)
• Weapon size should track resource availability more than any mandatory body part (similarity 0.88)
• Weapons in arms races get so big they impair other bodily functions (similarity 0.87)
• Weapons grow late because development prioritizes mandatory survival expenses first (similarity 0.85)
• Weapon size honestly signals fighting ability because growth tracks health and nutrition (similarity 0.84)
• Early survival advantages compound into huge adult differences in weapon resources (similarity 0.83)
• Weapon growth widens the gap between the best- and worst-armed males. (similarity 0.82)
• Weapons are better signals than body size because they vary from zero to enormous (similarity 0.81)
• Horn growth is nine times more nutrition-sensitive than genitalia in beetles (similarity 0.81)
• Big weapons only benefit males with the reserves to wield them effectively (similarity 0.81)
• Weapons evolve only when reproductive benefits exceed costs (similarity 0.81)
• Animal weapons evolved to extremes far beyond practical size (similarity 0.80)
• Extreme weapon size is relative to body size, not absolute (similarity 0.79)

Broader Connections

• Growing large weapons diverts resources and stunts other body parts #expands (0.80) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295
• Weapon size should track resource availability more than any mandatory body part #corroborates (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 338